The present invention relates to the sorting of spinning bodies with respect to their thread break number and/or with respect to the length of the spinning product wound thereon. The term "spinning bodies" as used herein refers to bobbins formed on ring spinning machines as well as cross-wound bobbins produced on open end machines.
The progressive automation of the working steps in the textile spinning process has lead to the fact that the ejection of the finished spinning bodies and the creeling of the empty tubes is also effected automatically. The full spinning bodies are removed from the spinning stations and are transferred to a conveyor belt of a transport installation. A transport installation of this type for ring spinning machines is described, for example, in the doffer installation of Swiss Pat. No. 556,404. In this installation, the spinning bodies are deposited in exactly the same sequence as they were arranged on the spinning rail. When the spinning bodies have been deposited on the conveyor belt, the belt is activated and the spinning bodies fall into a container. Quality-conscious spinning factories require the spinning operators to eliminate spinning bodies which have thread breaks, since it is known that these spinning bodies produce difficulties in further processing in subsequent production steps.
Moreover, spinning machines are provided with thread break detectors. For example, in the case of ring spinning, this detector comprises a sensor which scans the spinning stations or, in the case of open-end spinning, comprises an electro-mechanical thread sensor which is installed at each spinning station and which reports to a central evaluation device when there is a thread break at a spinning station. The relevant spinning stations are identified in the evaluation device and the position of the spinning bodies and the thread break numbers associated therewith and thread break durations (standstill times) are stored in the form of data. The thread break number is a measurement for the yarn quality and the thread break duration is a measurement for the yarn length of the correspondingly-produced spinning body.